Aryl carbamates



United States Patent O 3,428,669 ARYL CARBAMATES Delta W. Gier, Parkville, and Ralph W. Pritchard H,

Kansas City, Mo., assignors to Chemagro Corporation,

New York, N.Y., a corporation of New York No Drawing. Filed Mar. 11, 1965, Ser. No. 439,056 US. Cl. 260-471 Claims Int. Cl. C07c 79/46; A01n 9/20, 5/00 ABSTRACT OF THE DISCLOSURE The compounds are prepared having the formula:

ll R

X Ym

where X is chlorine, Y is nitro, Z is selected from the group consisting of methyl and hydrogen, R is selected from the group consisting of phenyl, tolyl and chlorophenyl and R is selected from the group consisting of hydrogen, phenyl, tolyl, chlorophenyl, alkyl and cycloalkyl, where n and m are integers from 1 to 3 and p is an integer from 0 to 3. The compounds are useful as defoliants, disiccants, fungicides and nematocides.

The present invention relates to novel carbamates.

It is an object of the present invention to prepare novel aromatic carbamates.

Another object is to prepare novel carbamates which are useful as pesticides.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

It has now been found that these objects can be attained by preparing carbamates having the formula where X is chlorine, Y is nitro, Z is methyl or hydorgen, R is phenyl, tolyl or chlorophenyl, R is hydrogen, phenyl, tolyl, chlorophenyl, alkyl or cycloalkyl, n and m are integers from 1 to 3 and p is an integer from 0 to 3 inclus1ve.

The novel carbamates are useful as desiccants, e.g. to desiccate cotton, as fungicides, e.g. as soil fungicides, foliar fungcides, seed protectants and seed disinfectants and, to a lesser extent, as nematocides, e.g. as saprophytic nematocides and as defoliants.

The carbamates can be prepared in the manner taught in Lambrech Patent 2,933,383 by using aromatic amines Patented Feb. 18, 1969 rather than aliphatic amines. More preferably, however, those compounds where R is hydrogen are prepared in the manner set forth below.

REACTION 1 One mole of the appropriate phenol was placed in a round bottom flask equipped with a reflux condenser, 500 ml. of carbon tetrachloride was added as a solvent. One mole of the appropriate aromatic isocyanate and a catalytic quantity of pyridine (0.5 ml. of pyridine) was added and the mixture wasrefluxed for three hours. After standing overnight 300 ml. of hot n-hexane was added. The crude carbamate was precipitated upon cooling, collected by filtration, washed with cold n-hexane and recrystallized from hexane or benzene-hexane mixture.

In preparing the compounds employed in the present invention by Reaction 1 as phenols there can be employed 2,4,5 trichloro-6-nitrophen0l, 2,6-dichlor0-4-nitrophenol, 2,4-dichloro-6-nitrophenol, 4-chloro-2,6-dinitrophenol, 2- chloro-4-nitrophenol, 3-chloro-4-nitrophenol, 4-chloro-2- nitrophenol, 4-chloro-3-methyl-2-nitrophenol, 2,4,6 trichlro-3-nitrophenol, 2,5-di-chloro-4-nitrophenol, 2,3-dichloro-6-nitrophenol, Z-chloro-S-nitrophenol, 4-chloro-2- methyl-6-nitr0phenol, 4-chloro-2,3-dimethyl-6-nitrophenol and 2-chloro-3,S-dinitrophenol.

As isocyanates which can be employed in Reaction 1 there can be used phenyl isocyanate, o-tolyl isocyanate, -m-tolyl isocyanate, p-tolyl isocyanate, o-chlorophenyl isocyanate, m-chlorophenyl isocyanate, p-chlorophenyl isocyanate, 2,4-dichlorophenyl isocyanate, 2,4,6-trichlorophenyl isocyanate, 2,4,5-trichlorophenyl isocyanate, 2,6- dichlorophenyl isocyanate, 2,5-dichlorophenyl isocyanate, 3,4-dichlorophenyl isocyanate, 2,3,4-trichlorophenyl isocyanate.

Typical examples of carbamates which have been prepared by Reaction 1 and their melting points and yields are set forth in Table 1.

TABLE 1 Compound M.P., Yield,

0. Percent 2,4,5-trichloro-G-nitrophenyl N-phenyl carbamate. 104-106 63 2,4,fi-tr1chloro-6-nitrophenyl N -chlorophenyl caro bamate 142-144 60 2,4,fi-trichloro-fi-nltrophenyl N-p-chlorophenyl carbamate 139-141 66 2,4,E-trichloro-G-nltrophenyl N -o-tolyl carbamate 157-159 36 2,4,5-trichloro-6-nitrophenyl N-m-tolyl carbamate... 150-154 25 2,6-dichloro-4-nitrophenyl N-p-ehlorophenyl earbamate 149-152 71 2,4-dlchloro-6-nitrophenyl N-phenyl earbamate. -103 49 2,4-dlchloro-6-nitrophenyl N-o-chlorophenyl earbamate 116-118 56 2,4-diehl0ro-6-nltropheny1 N-m-chlorophenyl carbamate 8-120 47 2,4-dichloro-fi-nltrophenyl N-p-chlorophenyl carbamate 118-119 52 2,4-dlchloro-6-nitrophenyl N-o-tolyl earbamate -112 26 2,4-diehloro-6-nltrophenyl N-m-tolyl carbamate 112-115 44 4-chloro-2,6-dinltrophenyl N-p-ehlorophenyl carbamate 97-99 97 2-ehloro-4-nitrophenyl N-p-chlorophenyl carbamate -142 100 3-chloro-4-nitrophenyl N -p-chlorophenyl earbamate -156 100 4-ch1oro-2-nitrophenyl N-p-chlorophenyl carbamate. 166-168 97 4-chloro-3-methy1-2-nitrophenyl N-p-chlorophenyl carbamate -162 100 Other carbamates within the present invention include 2,4,6 trichloro 3 nitrophenyl N-o-chloro-phenyl carbamate, 2,4,6-trichloro-3-nitrophenyl N-phenyl carbamate, 2,5-dichloro-4-nitrophenyl N-phenyl carbamate, 2,4,5-trichloro 6 nitrophenyl N-2,4-dichloro-phenyl carbamate,

3 2,4,5-trichloro-6-nitrophenyl N-2,4,6-trichlorophenyl carbamate, 4-chloro-3-methyl-2-nitrophenyl N-2,4,5-t1'ichlo rophenyl carbamate, 4-chloro-3-methyl-2-nitrophenyl N- phenyl carbamate, 2-chloro-3-methyl-4-nitrophenyl N-ptolyl carbamate.

There can also be made N,N disubstituted carbamates. These latter type compounds are prepared by the method of Lambrech replacing the secondary aliphatic amines by secondary aromatic amines such as N-methyl aniline, diphenyl amine, di-p-chlorophenyl amine, di-o-chlorophenyl amine, di-p-chlorophenyl amine, di-m-chlorophenyl amine, di-(2,4-dichlorophenyl) amine, di-(2,4,6- trichlorophenyl) amine, di-p-toyl amine, di-m-tolyl amine and di-o-toly amine.

Examples of carbamates prepared by this latter-procedure are 4-chloro-2-nitrophenyl N,N-diphenyl carbamate, 2,4,5 trichloro 6 nitrophenyl N,N-diphenyl carbamate, 2,4,5-trichloro-6-nitrophenyl N,N-di-p-chlorophenyl carbamate, 2,4,5-trichloro-6-nitrophenyl N,N-di-o-tolyl carbamate, 2,4,5-trichloro-6-nitrophenyl N-methyl, N,-phenyl carbamate, 2,4,5 trichloro 6-nitrophenyl N,N-di-(2,4,6- trichlorophenyl) carbamate, 2,4,5-trich1oro-6-nitropheny1 N,N-di-(2,4-dichlorophenyl) carbamate.

Compounds within the present invention had noticeably enhanced desiccant activity as compared to similar compounds which did not have at least one nitro group.

In one test at 4 lbs. of active ingredient per acre the defoliation and desiccation of cotton plants two weeks after application was as set forth in Table 2.

listed as saprophytic nematocides against Panagrellus spp., and Rhabditis spp., at a rate of 200 p.p.m., there was obtained the percent kill set forth in Table 3.

TABLE 3 Compound: Percent kill 2,4,5 trichloro 6 nitrophenyl p-chlorophenyl carbamate 2,4,5-trichloro 6-nitrophenyl o-tolyl carbamate 30 2,4,5 trichloro 6 nitrophenyl m tolyl carbamate 30 2,4-dichloro-6-nitrophenyl o-chlorophenyl carbamate 100 2,4-dichloro-6-nitrophenyl m-chlorophenyl carbamate 30 2,4-dichloro-6-nitrophenyl p-chlorophenyl carbarnate 100 The last compound in Table 3 was still 100% effective at a rate of 100 p.p.m.

The compounds of the present invention also showed fungicidal activity in several tests. Thus at a rate of 1000 p.p.m., the following compounds prevented spore germination of Alternaria spp.

2,4,5-trichloro-6-nitrophenyl-N-o-chlorophenyl carbamate;

2,4,5-trich1oro-6-nitrophenyl-N-m-chlorophenyl carbamate;

2,4,S-trichloro-6-nitrophenyl-N-p-chlorophenyl carbamate;

2,4-dichloro-fi-nitrophenyl-N-o-chlorophenyl carbamate;

2,4-dichloro-6-nitrophenyl-N-m-chlorophenyl carbamate;

2,4-dichloro-6-nitrophenyl-N-p-chlorophenyl carbamate;

Several of the compounds still showed slight inhibition of the spore germination at a rate as low as 10 p.p.m.

In agar plate fungicide tests, the results are set forth in Table 4. In the table, 0 indicates no inhibition and 10 indicates complete inhibition of fungi growth, X, Y and R are as set forth in Formula I. The fungi are abbreviated in the following manner:

P is Pythium irregulare C is Colletotrichum obiculare von Arx As a rule at the end of one week after application, F is fuswrium lycopersici desiccation was to complete while defoliation H is Helminthosporium sativum was 0 to 70% complete. R is Rhizoctonia solani When the compounds of the present invention were Vis Verticillium alba-atrum TABLE 4 Rate Organism x Y R (p.p.m.)

C F H R V 1,000 10 10 10 2,4,5-trlc11loro-.... 6-nitroo-Ghlorophenyl 1 533 1g 1g 13 2,4,5-trichl0r0-. 6-n1trom-Chlorophenyl. 0 o 0 2,4,5trlchloro- 6-nltr0- p-Ohlorophenyl.... 83 3 g 3 500 8 s 10 2,4,5-trieh1oro- 6-nltro-... o-Tolyl 100 5 8 8 10 2 5 a 500 8 S 10 2,4,5-trichloro-..-. 6-nitro-.. m-Tolyl 100 5 8 8 10 0 5 s 000 10 10 10 2,4-diehlor0- 6-nitroo-Chloropheny1 100 10 10 10 10 10 10 10 1,000 10 10 10 2,4-dichloro- 6-nitrom-ChlorophenyL.-. 100 10 10 10 10 10 10 10 1,000 10 10 10 2,4-dlchloro- 6-nltr0- p-Ch1orophenyl 100 10 10 10 Y 10 10 10 10 where X is chlorine, Y is nitro, Z is selected from the group consisting of methyl and hydrogen, R is selected from the group consisting of phenyl, tolyl and chlorophenyl and R is selected from the group consisting of hydrogen, phenyl, tolyl, chlorophenyl, methyl, n and m 20 are integers from 1 to 3 and p is an integer from 0 to 3. 2. A compound according to claim 1 in which R is hydrogen.

3. A compound according to claim 1 wherein n is 1 to 3, m is -1 to 2, R is selected from the group consisting 25 of phenyl and tolyl and Z is hydrogen.

4. A compound according to claim 3 wherein n is 2 andmis 1.

5. A compound according to claim 3 wherein n is 3 and m is 1.

6. A compound according to claim 1 wherein n is 1 to 3, m is 1 to 2, R is chlorophenyl having 1 to 3 chlorine atoms and Z is hydrogen.

7. A compound according to claim 6 wherein n is 2 and m is l.

8. A compound according to claim 1 wherein n is 1, m is 2, R is phenyl, R is mono chlorophenyl and Z is hydrogen.

9. A compound according to claim 1 wherein n is 3, m is 1 and R is chlorophenyl and Z is hydrogen.

10. A compound according to claim 1 wherein n is 1, m is 1, R is mono chlorophenyl and Z is methyl.

References Cited UNITED STATES PATENTS Re. 24,868 9/1960 Beaver et a1. 260-471 2,933,383 4/1960 Lambrech 260471 2,945,877 7/1960 Zima et al. 260-471 LORRAINE A. WEINBERGER, Primary Examiner.

L. A. THAXTON, Assistant Examiner.

U.S. Cl. X.R. 

